Purpose: Obesity by definition is the accumulation of abnormal fat due to an imbalance between energy intake and energy expenditure. Moreover, it is a leading cause of death that affects the overall quality of life and has serious health effects, for example, arthritis, insulin resistance, diabetes hypertension, heart failure and dyslipidemia. Untreated Insulin resistance state may lead to type II diabetes and lipotixicity by increasing the serum free fatty acids. Treatment of obesity is usually personalized and it includes life-style changes, therapeutic treatment options and surgery. However, going back to nature is an ongoing trend. Anti-obesity supplements from natural sources is a progressing trend as patients believe that they are safer compared to chemical agents. The nutraceutical agents used in this study are the widely marketed Raspberry ketone (RK). Previous studies were conducted to document the mechanism of RK, yet its effect on insulin resistance and insulin signaling downstream trajectories are not clear. Despite its known dietetic effect, however, the metabolomic/signaling pathways involved in this effect is not fully elucidated. Hence, our study comprehends the possible trajectories of using RK against obesity and insulin resistance.
Adult male Wistar rats were divided into 3 groups: group 1: normal chow diet (ND), group 2: high fat fructose diet (HFFD) and group 3: HFFD+RK (55mg/kg) To assess our aim, we determined the effect of RK on body weight, Intraperitoneal glucose tolerance test, glucose homeostasis (glucose, insulin, HOMA IR), lipid profile parameters and SREBP-1c, oxidative stress markers, insulin signaling pathways (p-IRS-1/p-AKT/GLUT-4), as well as liver and adipose tissue histopathology.
RK caused weight loss, corrected the disturbed glucose and insulin homeostasis, raised serum levels of HDL and decreased all other lipid profile parameters. it also increased Nrf-2 expression, ad GSH, as well as p-IRS-1/p-Akt/GLUT-4 cue, while it decreased MDA and SREBP-1c content compared to the HFFD group. Furthermore, the RK abolished apoptosis, decreased fatty changes and inflammation in hepatocytes and decreased sclerotic blood vessels and congestion in adipose tissue.
This study shows the contribution of p-IRS-1/p-AKT/GLUT-4 cue in the dieting effect of RK, as well as insulin sensitization. Additionally, RK administration efficiently rebalanced the redox status and Visceral and epididymal adipose tissues fat deposition confirmed histopathologically. Further studies are needed to additionally clarify other pathways that may be involved in RK dieting effect.
Reem Attia– Assistant lecturer, Future University in Egypt, Cairo
Yousra Abdel-Mottaleb– Lecturer, Future University in Egypt (FUE)
Dalaal Abdallah– Professor, Cairo University
Hanan El-Abhar– Professor, Future University in Egypt (FUE)
Nabila El-Maraghy– Professor, Future University in Egypt (FUE)
Reem Attia– Future University in Egypt, Cairo